1. Field of the Invention
The present invention relates to a device for monitoring a fan and in particular to a device having the effects of monitoring the status of bearings and predicting the remaining lifetime of the bearings, further achieving the effects of convenient operation and cost reduction.
2. Description of Prior Art
A cooling fan, a common heat dissipating structure, mainly provided in the electronic components, electric components, or machine generating heat, can be actuated to exhaust and dissipate the generated heat, fulfilling the purpose of cooling. Thus, the electronic, electric and mechanical components can be protected from high temperature which may cause damage or affect the operation to extend the lifetime thereof. Therefore, the cool fan is widespreadly installed in the currently common computer hosts, video recorders, and copiers.
The continuous operation of the cooling fan of prior art mainly relies on the relative movement of a bearing therein with respect to the axis of the cooling fan, so the bearing is one of the important key components which affect the quality of the cooling fan. Thus, the lifetime of the bearing is very important.
However, when the bearing of prior art is tested, it is installed in a bearing box of a bearing testing machine and is pivotally connected to the axis of the motor. Then, an accelerometer or a sensor of the same type is disposed on the bearing (or around the bearing) and is electrically connected to a digital signal processor (DSP). When the motor drives its axis, the bearing will move with respect to the axis. At this time, the vibration caused by the operating bearing is sensed by the accelerometer and a vibration signal is then generated. After that, the status of the bearing (e.g., the bearing is normal or abnormal) can be acquired by the analysis processing through the DSP based on the received vibration signal.
For the prior art, the status of the bearing can be obtained during the bearing testing, however, resulting in another problem. Due to the space limitation on the bearing testing machine, it is awkward for the accelerometer to be placed and also the cost of the accelerometer is considerable. Further, the use of DSP causes computational processing of great complexity.
The above prior art suffers the following disadvantages:                1. Limitation on installation in which the accelerometer is awkward to be placed; and        2. Cost is increased.        
Therefore, how to overcome the above problems and disadvantages is the focus which the inventor and the related manufacturers in this industry have been devoting themselves to.